Accessing top_block from an embedded python block?

Hello!

I am new to using GNU radio, and i would like to implement some custom features.

I would like to access functions like the get_push_button to read its state, or read a message box etc.

Is this even possible from the epy block?

I could also implement this directly in the top_block.py file, but my problem is that if i want to change something in the GUI, this file is overwritten, and the custom code will be erased. Or am i missing something?